This invention is related to the extinguishing of fires in oil wells and the like. In particular, it is a method and means of keeping oxygen from the combustion region of an oil well fire and also of cooling that region so that the fire will go out.
A fire in an oil well in which the oil is under pressure from the earth presents a difficult problem. To control the fire it is necessary to extinguish the flames so that the well can be capped to stop the flow of oil. The site of a burning well is typically unreachable by work crews because of the high temperatures associated with the fire. The well-known ways of extinguishing fires include, alone or in combination, preventing oxygen from reaching the combustible materials, cooling the combustible materials below their ignition temperature, and removing the source of combustible materials. The final step of capping the well or installing a device which permits control of the flow will eventually achieve the objective of removing combustible materials from the fire scene. The first objective, therefore, must be to put out the fire so crews can reach the well to control the flow.
The traditional method of fire fighting by spraying a fire with water is of little use in fighting oil fires. While some secondary benefit might be obtained from the cooling effect of the water, the immiscibility of oil and water assures that the water does not wet the oil and therefore that the oil that is being heated by the flames is not appreciably cooled.
Carbon dioxide has long been used as a fire-extinguishing medium. It is non-combustible and is denser than air in its gaseous state, so it tends to blanket an area around a fire when sprayed on the fire. However, delivery of carbon dioxide to a fire by means of a horn or the like tends to be ineffective on a fire in an oil well or other such source of combustible fluid under pressure that flows to feed the fire. Such a fire is best extinguished by some combination of cooling the surroundings of the fire and also excluding oxygen until the fire is out.
While fires in oil wells are of particular present concern, it should be noted that methods and means for putting out fires in oil wells are usually equally as effective in controlling fires in natural gas wells and pipeline leaks.